have test runner print message when started

[jpiesing]

Split out from the Zach Cava comments in #38 .

o Startup is just fine, might be nice to have the tests print "Runner ready" on command line since there are a few long-pauses during startup

[jpiesing]

February 20th meeting
Requires changes to W3C test runner. Will do this during the next WMAS release cycle when a pull request is created towards the W3C. Perhaps before the end of April.

[FritzHeiden]

I merged performance improvements for the start-up of the test runner (#130), which eliminates long pauses. This may eliminate the need for this feature. wdyt?

[jpiesing]

IMHO this is a "nice to have". If it's complex to implement due to WPT test runner changes then so be it.